the game is really cute and fun, but i have a few suggestions:
1- Its really hard to know when you get hit,so something like a screen shake or hit sound would be nice
2- The background feels kinda flat,so a paralax background would be nice i think
3- The shotgun could have recoil,that would be interesting for plataforming around
4-The water works weirdly
Well thats all but its just my opinion,but overall a really nice game :)